Odd draft bug

Okay, my friend didn't accept many games, and we didn't know he had to go somewhere. After he came back, it wouldn't let me start a game. It wouldn't let me leave . So i had to restart my computer, and i made another q. Yet it wouldn't let me , and my other friends tried, but it happened to them . I made another w, and it says my friend has leaver buster. and he said he didn't (with all my other friends). So we're waiting in a leaverbuster that only i can see.Can you tell me how to fix this problem so it wouldn't happen again ?